Kalirin, also known as Huntingtin-associated protein-interacting protein (HAPIP), protein duo (DUO), or serine/threonine-protein kinase with Dbl- and pleckstrin homology domain, is a protein that in humans is encoded by the KALRNgene. Kalirin was first identified in 1997 as a protein interacting with huntingtin-associated protein 1. Is also known to play an important role in nerve growth and axonal development.
Kalirin is a member of the Dbl family of proteins and is a Rho guanine nucleotide exchange factor. It is named after the multiple-handed Hindu goddess Kali for its ability to interact with numerous other proteins. Kalirin's other name, DUO, comes from the fact that it is 98% identical to rat DUO protein and 80.6% identical to a human protein named TRIO. Unlike TRIO, which is expressed in numerous tissues, Kalirin isoforms are mainly found in the brain.
^Youn H, Ji I, Ji HP, Markesbery WR, Ji TH (November 2007). "Under-expression of Kalirin-7 Increases iNOS activity in cultured cells and correlates to elevated iNOS activity in Alzheimer's disease hippocampus". J. Alzheimers Dis. 12 (3): 271–81. PMID18057561.
^Youn H, Jeoung M, Koo Y, Ji H, Markesbery WR, Ji I, Ji TH (June 2007). "Kalirin is under-expressed in Alzheimer's disease hippocampus". J. Alzheimers Dis. 11 (3): 385–97. PMID17851188.